BRUSSELS - NATO leaders on Wednesday called on all nations to maintain "decisive pressure" on North Korea, including by fully implementing United Nations sanctions, to persuade it to give up it nuclear, chemical and biological weapons.

The allies also expressed concern about Iran's intensified missile tests and said the alliance was committed "to permanently ensuring that Iran’s nuclear program remains peaceful".

The summit declaration signed by the 29 NATO leaders reiterated the alliance's full support for the goal of "complete verifiable and irreversible denuclearization of the Korean Peninsula."

It welcomed recent talks with North Korea by the leaders of South Korea and the United States "as a contribution towards reaching the final fully verified denuclearization of (North Korea) in a peaceful manner".

"We call upon [North Korea] to fully implement its international obligations; to eliminate its nuclear, chemical, and biological warfare capabilities and ballistic missiles, and abandon all related `programs," the statement said.

It also called on North Korea to return to the Treaty on Non-Proliferation of Nuclear Weapons and to accede to the Chemical Weapons Convention.

"We call on all nations to maintain decisive pressure on [North Korea], including by fully implementing existing UN sanctions," the statement said.